1. Field of the Invention
The present invention relates to a door construction which covers and uncovers an opening formed in a vehicle such as a door cut-out for a passenger to get in and out of the vehicle, and more particularly to a door construction having a side impact bar.
2. Description of the Related Art
A side impact bar having a square, angled or round cross section is disposed in an interior of a door which covers and uncovers an opening formed in a vehicle in such a manner as to be connected to front and rear ends of the door at ends thereof in order to enhance the safety against a collision from a side of the vehicle. An opening is formed in an inner panel of the door which is made use of when mounting various types of equipment such as a window regulator for raising and lowering a window glass. There are a couple of types of window regulators: one in which a window glass is raised and lowered using gear wheels and link mechanisms; and the other as described in JP-A-5-156861 in which a wire is extended between pulleys arranged in a vertical direction of a door to cross in an X-shape and part of the wire so extended is wound round a drum, whereby winding directions of the drum is changed by a regulator motor which is a drive source so as to raise and lower a window glass.
In JP-A-5-156861, a rail member having an angled or U-shaped cross section which guides the ascending and descending of the window glass is fixed to a side impact bar, and the pulleys are rotatably supported on a bracket which is fixed to the rail member.
In JP-A-5-156861, while a drive device (a rotary drum, a motor and the like) of the window regulator is mounted on a side beam via a bracket connected to the side beam at one end thereof, since the bracket extends below the side beam, in a case where a side door beam has a transverse width (a width in a width direction of the vehicle), the width of the rotary drum which makes up the window regulator is added to the width of the side door beam, constituting a cause for a disruption against an attempt to reduce the thickness of the door. Overall widths of vehicles are regulated for classifications of vehicles. In particular, in small-sized vehicles whose overall width is regulated to be narrow, since a width of a passenger compartment depends on a width of a door, when attempting to secure as wide as possible a space within a passenger compartment, the reduction in a ratio of the transverse width of the vehicle which is occupied by doors, that is, the reduction in thickness of the door constitutes a very important factor to be considered. When attempting to simply reduce the thickness of the door, the attempt can be accomplished by reducing the width of a side impact bar, but with this adopted in reality, the impact absorption capability at the time of side impact is reduced. In addition, since the bracket is supported at only one end thereof, there is caused a risk that a sufficient mounting rigidity cannot be secured.